The invention relates to a sun roof for vehicles having a roof opening which sun roof comprises a cover for the opening and a rolled up sun protective screen adapted to extend beneath the cover.
The covers of such sun roofs can be lifted up or pushed along. The covers consist of a transparent material which lets through both the light and sun radiation. For protection against such radiation, sun protective screens mounted on a side of the cover or frame are used (German Disclosure Nos. 3,000,280 and 3,242,097). Such screens comprise a rigid frame having approximately tne size of the roof opening, and the screens may have slits which can be opened and closed with adjustable slit coverings to let more or less radiation and/or air pass through the slits. The known sun roofs have the disadvantage of being obstructive and passing not enough light, so that the feeling, usually given by sun roofs, of increased head room and pleasant light and air conditions, is impaired. Also, with the known sun protective screens, in the case of slit coverings which can be pushed along, less than 50% of the roof openings is free for unhindered passage of radiation. Snapped up slip coverings, which may be used as an alternative and which have a greater cross section area, are very complex and can hardly be kept free from snapping noises.
It is also known (German Disclosure 2,313,840) to roll up and unroll sun protective screens for vehicle roofs, or use rolling protection nets for sliding roofs (German Disclosure 2,636,749). The disadvantage of these types of devices consists in that the former requires complicated roof frames for mounting outside on the vehicle, and the latter are only effective when the slide roof is opened. Such roller devices are completely unsuitable, however, for sun roofs of the kind mentioned.
German Published Application 1,102,581 discloses a sun roof in which two winding shafts disposed at an angle to each other and joined in the middle with a hinge, are provided for the roller. In this known roller device, the rolled material must have an excessive length since otherwise the roller device would not function. Therefore, the rolled material hangs through badly in the middle. If there is no excess material, or, correspondingly, elastic rolled material is used, the winding shaft of the roller device cannot turn because of the geometric conditions, since the total length in the underside is necessarily less than on the upper side. The function of this known roller device is, therefore, jeopardized, since with horizontal pull of the rolled material, a moment of rotation in the pulling direction acts on the middle part of the winding shaft which is bent upward. It can hardly be imagined that generally simple end bearings of the winding shaft will be able to withstand the torsion applied to them. Rather, it may be assumed that the curve, formed by the winding shafts will be tilted in the horizontal direction by the pull on the roller material, and the roller material will hang through even more. It is doubtful that this known roller device is actually suitable for use on curved vehicle roofs. In any case, there is to be feared a hanging through of the rolled material that reduces head room in the vehicle space.
Moreover, the bending of the winding shaft makes it necessary, for the guiding of the rolled material in a curve corresponding to the arching of the vehicle roof, to arrange a rail below the roof frame, designed as a guide slot. This undesirably limits head room as compared with the head room given by the sun roof and its frame.
German Disclosure No. 1,530,636 discloses a roller device for vehicle sun roofs which can be equipped with a rigid base part. Placing this one-piece roller on arched vehicle roofs is possible only with considerable loss of head room.
German Disclosure No. 1,430,922 discloses a sun roof, in which the closing element has no rigid cover, can rather be rolled up, guided on its side edges extending in the pulling direction. This sun roof has no rigid cover of its own. The rolled material which can be rolled up can fulfill its function as closing element (sealing, of course), only if the vehicle roof is concave, thus, opposite the usual convex arching. Only in this way is it possible that, with an arrangement of the winding shaft within the raised roof frame, the closing element, which can be rolled up, will lie tightly against the opening edge of the roof opening.
Finally, French Pat. No. 1,511,431 discloses a sun roof that has the same disadvantages as the sun roof of German Disclosure No. 1,530,636.
The object of the invention is a sun roof of the kind mentioned that has a roller device which can be integrated into the vehicle body, especially into its roof opening so that it does not reduce the head room for the passengers, which roller device has little obstructive mass, is suitable for curved vehicle roofs, can be used with a cover which is opened, closed or removed, and especially with a cover which can be lifted up at its rear edge, and the necessary parts of which do not impair the aesthetic appearance of the sun roof, and which provides wide variations in the sun protection effect, especially for the driver and the front seat passenger. Such a roller device should be such that it can be mounted later. The sun protective screen should be able to cover between about 0 and 100% of the roof opening area. The roller device also should be such that it is possible to use it in connection with a frame, especially a plastic frame, supported in a manner known per se at the opening edge of the vehicle roof.